GM R&D Develops and Demonstrates Strontium-Doped Perovskite Catalysts Rivaling Platinum Catalysts for NOx Control in Diesel Exhaust; Lower Cost Could Be a Boost for Diesel

NOx conversion profiles. Commercial LNT (black dashed line); La0.9Sr0.1MnO3-based LNT (green line); La0.9Sr0.1MnO3-based LNT after a S loading of 1 g liter–1 catalyst (red line); and La0.9Sr0.1MnO3-based LNT after desulfation (blue line) as a function of temperature. Credit: Kim et al. Click to enlarge.

Researchers from the General Motors Global Research and Development, Chemical Sciences and Materials Systems Lab have developed and demonstrated the use of strontium-doped perovskite oxides as efficient platinum substitutes in diesel oxidation (DOC) and lean NO_x trap (LNT) catalysts. Their work may help to lower the cost of NO_x treatments and thus ultimately make diesel a more cost-effective automotive fuel. A paper on the work was published in the 26 March issue of the journal Science.

One of the obstacles to the more widespread adoption of diesel engines—especially in the face of increasingly stringent emissions requirements—is the requirement for a lean NO_x aftertreatment system. The aftertreatment system is a key contributor to the cost premium for diesel vehicles.

A typical diesel aftertreatment system will include a diesel oxidation catalyst to oxidizes hydrocarbons, CO, and NO, followed by NO_x reduction. The two leading technologies for NO_x reduction in the oxygen-rich environment are ammonia selective catalytic reduction (SCR) and a lean NO_x trap (LNT)